Chapter 5

Question 1

Enantiomer

Answer 1

A molecule that is not identical to its mirror image is a kind of stereoisomer. Have identical physical properties, such as melting point and boiling point, but differ in the direction in which their solutions rotate plane-polarized light.

Question 2

Chiral

Answer 2

A molecule that is not identical to its mirror image.

Question 3

Achiral

Answer 3

A molecule that has a plane of symmetry in any conformation must be identical to its mirror image and must be non……..

Question 4

Chirality center

Answer 4

Tetrahedral carbon atom bonded to four different groups.

Question 5

Optically active

Answer 5

The plane of polarization is rotated through an angle of an organic molecule.

Question 6

Polarimeter

Answer 6

The angle of rotation can be measured with an instrument called…..

Question 7

Levorotatory

Answer 7

Some optically active molecules rotate polarized light to the left (counterclockwise)…..(-)

Question 8

Dextrorotatory

Answer 8

Some optically active molecules rotate polarized light to the right (clockwise)…..(+)

Question 9

R Configuration

Answer 9

If a curved arrow drawn from the highest to second- highest to third-highest ranked substituent (1,2,3) is clockwise. We say that the chirality center has the…….

Question 10

S configuration

Answer 10

If an arrow from (1,2,3) is counter clickwise, the chirality center has the…..

Question 11

Optical rotation vs absolute configuration

Answer 11

Note that the sign of optical roation, (+) or(-) is not related to the R,S designation. There is no correlation.

Question 12

Diastereomers

Answer 12

Stereoisomers that are not mirror images. relationship between two ……. is like that of hands from different people. they aren’t identical and they aren’t mirror images.

Question 13

Enantiomers vs Diastereomers:

Answer 13

enantiomers have opposite configurations at all chirality centers, whereas diastereomers have opposite at some (one or more) chirality centers but the same configuration at others.

Question 14

Epimers

Answer 14

In the special case where two diastereomers differ at only one chirality center but are the same at all others……

Question 15

Meso compounds

Answer 15

Compounds, which are achiral, yet contain chirality centers, are called…..
They are different compounds all together with different physical properties and are not mirror images.

Question 16

Racemic Mixture or racemate

Answer 16

50:50 mixture of the two chiral enantiomers. denoted by the symbol (+-) or the prefix d,l to indicate an equal mixture of dextrorotatory and levorotatory forms. Which equal to optical rotation.

Question 17

Isomers

Answer 17

are compounds with the same chemical formula but different structures.

Question 18

Constitutional Isomers

Answer 18

are compounds whose atoms are connected differently. Among the kinds we’ve seen are skeletal, functional and positional isomers.

Question 19

Stereoisomers

Answer 19

Compounds whose atoms are connected in the same order but with a different spatial arrangement. Among the kinds we’ve seen are enantiomers, diastereomers, and cis-trans isomers of cycloalkanes. Cis-trans isomers are just a subclass of diastereomers because they are non-mirror image stereoisomers.